Display technology is evolving, including to the point where general consumers today can purchase 3D (three-dimensional/stereoscopic) televisions. In general, 3D televisions display separate video frames to each eye via 3D glasses with lenses that block certain frames and pass other frames through.
Spatial multiplexing is another recent advancement, in which a lenticular display uses lenses (parallax barriers/lenslets) in front of light sources (e.g., light emitting diodes/LEDs or liquid crystal displays/LCDs) to display separate views to different viewing angles (zones). The highest lenticular display, for example, enables nine separate views, whereby viewers of the display who are positioned at appropriate angles (e.g., zones ten degrees apart) can each see a different image at the same time.
However, spatial multiplexing comes at the cost of resolution, in that nine vertical columns of pixels on an LCD display, for example, are needed to produce a single effective column of pixels for each viewing angle in the nine-view display. Given the limited resolution of LCD displays, this one-ninth degradation of effective horizontal resolution is dramatic, particularly when considering that the effective vertical resolution is unchanged (and therefore significantly mismatched with the horizontal resolution).